In applications where the overall size of an electronic device must be limited, such as hearing aids, hybrid circuits are used to incorporate solid-state devices with discrete components. Such circuits typically incorporate one or more integrated circuits with thick film resistors, capacitors, and contact pads on a ceramic substrate. Components are interconnected using printed conductors. Where components are placed on both sides of the substrate vias are provided. The number of devices that can be accommodated on a single substrate is limited by the size of the components and the need to isolate signal paths from one another. In some cases multiple hybrid substrates must be interconnected to provide a large enough surface area to accommodate a complete circuit.
As electronic devices are scaled to smaller dimensions, utilization of space around the die becomes critical. Due to this scaling, connections from stacked die to die create design and manufacturing challenges. Interconnect techniques are needed that provide a greater number of interconnects, thereby providing hybrid manufacturers the opportunity to produce smaller and more powerful packages. The increased number of interconnects could be potentially used to add more functionality to the circuit or reduction of the final package size.